Organic light emitting display and method of fabricating the same

ABSTRACT

An organic light emitting display can include light emitting elements disposed on a substrate; an encapsulation unit disposed on the light emitting elements; touch sensors disposed on the encapsulation unit; first conductive lines connected to the touch sensors; second conductive lines connected to the first conductive lines; and at least one insulating film formed of at least one of an inorganic film or an organic film and disposed between the first and second conductive lines.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is Continuation of U.S. patent application Ser. No.16/666,105 filed on Oct. 28, 2019, which is a Divisional of U.S. patentapplication Ser. No. 15/637,728 filed on Jun. 29, 2017 (now U.S. Pat.No. 10,505,142 issued on Dec. 10, 2019), which claims priority under 35U.S.C. § 119(a) to Korean Patent Application No. 10-2016-0083006, filedon Jun. 30, 2016, all of these applications are hereby incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an organic light emitting display and amethod of fabricating the same, and more particularly, to an organiclight emitting display which can achieve weight reduction and slimming,and a method of fabricating the same.

Discussion of the Related Art

A touchscreen is an input device through which a user may input acommand by selecting instructions displayed on a screen of a display,using a hand or an object. That is, the touchscreen converts a contactposition directly contacting a human hand or an object into anelectrical signal and receives instructions selected at the contactposition as an input signal. Such a touchscreen may substitute for aseparate input device connected to a display device and operated, suchas a keyboard or a mouse, and thus applications of touchscreens havegradually increased.

In general, a touchscreen is attached to the front surface of a displaypanel, such as a liquid crystal display panel or an organicelectroluminescent display panel. In this instance, since thetouchscreen is separately manufactured and then attached to the frontsurface of the display panel, an attachment process is additionallyperformed and thus the overall process becomes complicated andmanufacturing costs are raised. Further, the overall thickness of thedisplay panel is increased by the touchscreen and it may be difficult tosecure flexibility and transmittance due to the increased thickness.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an organic lightemitting display and a method of fabricating the same that substantiallyobviates one or more problems due to limitations and disadvantages ofthe related art.

An object of the present invention is to provide an organic lightemitting display which can achieve weight reduction and slimming, and amethod of fabricating the same.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, anorganic light emitting display includes light emitting elements disposedon a substrate, an encapsulation unit disposed on the light emittingelements and including a plurality of inorganic encapsulation layers andat least one organic encapsulation layer disposed between the inorganicencapsulation layers, and touch sensing lines and touch driving linesdisposed so as to intersect each other such that at least one of theinorganic encapsulation layers and the at least one organicencapsulation layer is interposed therebetween.

Both the foregoing general description and the following detaileddescription of the present invention are exemplary and explanatory andare intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a plan view of an organic light emitting display having touchsensors in accordance with one embodiment of the present invention;

FIG. 2 is a cross-sectional view of the organic light emitting display,taken along line I-I′ of FIG. 1;

FIGS. 3A to 3D are plan and cross-sectional views illustrating a methodof fabricating the organic light emitting display shown in FIGS. 1 and 2according to an embodiment;

FIG. 4 is a plan view of an organic light emitting display having touchsensors in accordance with a further embodiment of the presentinvention;

FIG. 5 is a cross-sectional view of the organic light emitting display,taken along line II-IF of FIG. 4;

FIGS. 6A to 6F are plan and cross-sectional views illustrating a methodof fabricating the organic light emitting display shown in FIGS. 4 and 5according to an embodiment;

FIG. 7 is a cross-sectional view of an organic light emitting displayhaving touch sensors in accordance with another embodiment of thepresent invention;

FIGS. 8A to 8F are cross-sectional views illustrating a method offabricating the organic light emitting display shown in FIG. 7 accordingto an embodiment;

FIG. 9 is a cross-sectional view of an organic light emitting displayhaving touch sensors in accordance with another embodiment of thepresent invention;

and

FIG. 10 is a cross-sectional view of an organic light emitting displayhaving touch sensors in accordance with another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIGS. 1 and 2 are plan and cross-sectional views of an organic lightemitting display having touch sensors in accordance with one embodimentof the present invention.

An organic light emitting display having touch sensors shown in FIGS. 1and 2 includes at least one switching thin film transistor, at least onedriving thin film transistor 130, light emitting elements 120, anencapsulation unit 140, touch driving lines 152 and touch sensing lines154.

The at least one switching thin film transistor and the at least onedriving thin film transistor are formed on a lower substrate 111 formedof plastic or glass.

The switching thin film transistor is connected to a gate line and adata line at the intersection therebetween, and the driving thin filmtransistor 130 is connected to the switching thin film transistor and apower line.

The driving thin film transistor 130 includes, as an example shown inFIG. 2, a gate electrode 132, a semiconductor layer 134 overlapping thegate electrode 132 with a gate insulating film 112 interposedtherebetween, and source and drain electrodes 136 and 138 formed on afirst protective film 114 and contacting the semiconductor layer 134.

The light emitting element 120 includes an anode 122, an organic lightemitting layer 124 formed on the anode 122, and a cathode 126 formed onthe organic light emitting layer 124.

The anode 122 is conductively connected to the drain electrode 138 ofthe driving thin film transistor 130 exposed through a pixel contacthole formed through a second protective film 116. The organic lightemitting layer 124 is formed on the anode 122 in an emission regionprovided by a bank 128. The organic light emitting layer 124 is formedby stacking a hole-related layer, a light emitting layer and anelectron-related layer on the anode 122 in regular order or in reverseorder. The cathode 126 is formed opposite the anode 122 with the organiclight emitting layer 124 interposed therebetween.

The encapsulation unit 140 prevents external moisture or oxygen frompenetrating through the light emitting element 120, which is vulnerableto external moisture or oxygen. For this purpose, the encapsulation unit140 includes a plurality of inorganic encapsulation layers 142 and 146and an organic encapsulation layer 144 disposed between the inorganicencapsulation layers 142 and 146, and the inorganic encapsulation layer146 is disposed as the uppermost layer. Here, the encapsulation unit 140includes at least two inorganic encapsulation layers 142 and 146 and atleast one organic encapsulation layer 144. In the present invention, thestructure of the encapsulation unit 140 in which the organicencapsulation layer 144 is disposed between the first and secondinorganic encapsulation layers 142 and 146 will be exemplarilydescribed.

The first encapsulation layer 142 is formed on the substrate 111provided with the cathode 126 so as to be located most adjacent to thelight emitting element 120. The first encapsulation layer 142 is formedto expose touch driving pads 170 and touch sensing pads 180. Such afirst encapsulation layer 142 is formed to have a monolayer ormultilayer structure using an inorganic insulating material which can bedeposited at a low temperature, such as silicon nitride (SiN_(x)),silicon oxide (SiO_(x)), silicon oxynitride (SiON) or aluminum oxide(Al₂O₃). Therefore, damage to the organic light emitting layer 124 by ahigh-temperature atmosphere during a deposition process of the firstencapsulation layer 142 can be prevented.

The organic encapsulation layer 144 is formed to have a smaller areathan that of the first inorganic encapsulation layer 142 and exposesboth ends of the first inorganic encapsulation layer 142. The organicencapsulation layer 144 serves as a buffer to damp stress betweenrespective layers according to warpage of the organic light emittingdisplay and strengthens planarization performance of the organic lightemitting display. The organic encapsulation layer 144 is formed to havea monolayer or multilayer structure using an organic insulatingmaterial, such as acrylic resin, epoxy resin, a polymeric resin (forexample, polyimide or polyethylene) or silicon oxycarbide (SiOC).

The second inorganic encapsulation layer 146 is formed on the substrate111 provided with the organic encapsulation layer 144 formed thereon soas to cover the upper and side surfaces of the organic encapsulationlayer 144 and the first inorganic encapsulation layer 142. Therefore,the second inorganic encapsulation layer 146 minimizes or blockspenetration of external moisture or oxygen into the first inorganicencapsulation layer 142 and the organic encapsulation layer 144. Such asecond inorganic encapsulation layer 146 is formed to have a monolayeror multilayer structure using an inorganic insulating material, such assilicon nitride (SiN_(x)), silicon oxide (SiO_(x)), silicon oxynitride(SiON) or aluminum oxide (Al₂O₃).

The touch sensing lines 154 and the touch driving lines 152 are disposedso as to intersect each other such that at least one of the first andsecond inorganic encapsulation layers 142 and 146 and the organicencapsulation layer 144 of the encapsulation unit 140 is interposedtherebetween. In this embodiment of the present invention, a structure,in which the touch sensing lines 154 and the touch driving lines 152 aredisposed so as to intersect each other such that the uppermost layer,i.e., the second inorganic encapsulation layer 146, of the encapsulationunit 140 is interposed therebetween, will be exemplarily described.

The touch driving line 152 includes a plurality of first touchelectrodes 152 e, and first bridges 152 b to conductively connect thefirst touch electrodes 152 e.

The first touch electrodes 152 e are spaced apart from each other in theY-axis direction by designated intervals on the second inorganicencapsulation layer 146. Each of the first touch electrodes 152 e isconductively connected to the adjacent first touch electrode 152 ethrough the first bridge 152 b.

The first bridges 152 b are formed on the organic encapsulation layer144, are exposed through touch contact holes 150 formed through thesecond inorganic encapsulation layer 146, and are conductively connectedto the first touch electrodes 152 e. The first bridge 152 b is disposedso as to overlap the bank 128 and, thus, lowering of an aperture ratiodue to the first bridges 152 b can be prevented.

The touch sensing line 154 includes a plurality of second touchelectrodes 154 e, and second bridges 154 b to conductively connect thesecond touch electrodes 154 e.

The second touch electrodes 154 e are spaced apart from each other inthe X-axis direction by designated intervals on the second inorganicencapsulation layer 146. Each of the second touch electrodes 154 e isconductively connected to the adjacent second touch electrode 154 ethrough the second bridge 154 b.

The second bridges 154 b are disposed on the second inorganicencapsulation layer 146 so as to be coplanar with the second touchelectrodes 154 e, and thus are conductively connected to the secondtouch electrodes 154 e without separate contact holes. In the samemanner as the first bridge 152 b, the second bridge 154 b is disposed soas to overlap the bank 128 and, thus, lowering of an aperture ratio dueto the second bridges 154 b can be prevented.

Since the touch sensing lines 154 and the touch driving lines 152intersect each other with the second inorganic encapsulation layer 146interposed therebetween, mutual capacitances Cm are formed at theintersections between the touch sensing lines 154 and the touch drivinglines 152. Therefore, the mutual capacitance Cm is charged with chargesby a touch driving pulse supplied to the touch driving line 152 anddischarges the charges to the touch sensing line 154, thus serving as atouch sensor.

The touch driving lines 152 of the present invention are connected to atouch driving unit through first routing lines 156, first routing pads176 and the touch driving pads 170 disposed in an edge area. Further,the touch sensing lines 154 are connected to the touch driving unitthrough second routing lines 166, second routing pads 186 and the touchsensing pads 180 disposed in the edge area.

The first routing line 156 is conductively connected to the first touchelectrode 152 e through a first routing contact hole 158 and thustransmits a touch driving pulse from the touch driving pad 170 to thetouch driving line 152. The second routing line 166 is conductivelyconnected to the second touch electrode 154 e through a second routingcontact hole 168 and thus transmits a touch signal from the touchsensing line 154 to the touch sensing pad 180.

The first and second routing lines 156 and 166 are formed to have amultilayer structure. For example, each of the first routing lines 156has a structure in which a first routing conductive layer 156 a and asecond routing conductive layer 156 b are stacked, and each of thesecond routing lines 166 has a structure in which a first routingconductive layer and a second routing conductive layer are stacked.Here, the first routing conductive layer 156 a is formed to have amonolayer or multilayer structure using Al, Ti, Cu or Mo, and the secondrouting conductive layer 156 b is formed of an ITO, IZO, IGZO orZnO-based transparent conductive oxide, which is the same material asthe first bridges 152 b, on the first routing conductive layer 156 a.Therefore, if any one of the first and second routing conductive layers156 a and 156 b of each of the first and second routing lines 156 and166 is cut, the other conductive layer transmits a touch driving pulseand a touch signal.

The first and second routing pads 176 and 186 respectively extend fromthe first and second routing lines 156 and 166 and thus have a structurein which first and second conductive layers 156 a and 156 b are stackedin the same manner as the first and second routing lines 156 and 166.The first routing pads 176 conductively connect the first routing lines156 and the touch driving pads 170, and the second routing pads 186conductively connect the second routing lines 166 and the touch sensingpads 180.

Each of the touch driving pads 170 and the touch sensing pads 180includes a pad electrode 172 or 182 and a pad connection electrode 174or 184 disposed on the pad electrode 172 or 182 so as to cover the padelectrode 172 or 182.

The pad connection electrodes 174 and 184 of the touch driving pads 170and the touch sensing pads 180 are conductively connected to the firstand second routing pads 176 and 186 exposed through pad contact holes160 formed through the second inorganic encapsulation layer 146.Particularly, the pad connection electrodes 174 and 184 of the touchdriving pads 170 and the touch sensing pads 180 are disposed on theupper and side surfaces of the uppermost layer of the encapsulation unit140, i.e., the second inorganic encapsulation layer 146. Therefore, evenif external oxygen or moisture penetrates through the pad connectionelectrodes 174 and 184, the organic encapsulation layer 144 and thefirst and second inorganic encapsulation layers 142 and 146 block oxygenor moisture and may thus protect the organic light emitting layer 124from oxygen or moisture.

The pad electrodes 172 and 182 of the touch driving pads 170 and thetouch sensing pads 180 are formed of a first conductive layer, and thepad connection electrodes 174 and 184 are formed to have a structure inwhich third and fourth conductive layers 174 a and 174 b are stacked.Here, the third conductive layer 174 a is formed of an ITO, IZO, IGZO orZnO-based transparent conductive oxide, and the fourth conductive layer174 b is formed to have a monolayer or multilayer structure using metalshaving high corrosion resistance and acid resistance, such as Al, Ti, Cuand Mo. For example, the fourth conductive layer 174 b has a tri-layerstructure, such as Ti/Al/Ti or Mo/Al/Mo.

As such, in the organic light emitting display in accordance with thisembodiment of the present invention, the touch driving lines 152 and thetouch sensing lines 154 are disposed so as to intersect each other withthe second inorganic encapsulation layer 146 of the encapsulation unit140 interposed therebetween and, thus, a touch insulating layer disposedbetween touch driving lines and touch sensing lines is not required,thereby achieving structure simplification, weight reduction andslimming. That is, the organic light emitting display in accordance withthe present invention includes the first and second inorganicencapsulation layers 142 and 146 and the organic encapsulation layer 144of the encapsulation unit 140 disposed on the cathode 126 without aseparate touch insulating layer. Further, a related art organic lightemitting display includes an encapsulation unit having at least atri-layer structure, and at least one touch insulating layer included ina touchscreen including first and second touch electrodes. In thisinstance, the organic light emitting display in accordance with thepresent invention does not require a touch insulating layer, as comparedto the related art organic light emitting display, and can thus achievestructure simplification, weight reduction and slimming, assureflexibility and improve transmittance. Further, while, in the relatedart organic light emitting display, a touchscreen is attached to adisplay panel through an adhesive, in the organic light emitting displayin accordance with the present invention, the touch electrodes 152 e and154 e are disposed in the encapsulation unit 140, a separate attachmentprocess is omitted and, thus, process simplification and cost reductioncan be achieved.

FIGS. 3A to 3D are plan and cross-sectional views illustrating a methodof fabricating the organic light emitting display shown in FIGS. 1 and2.

With reference to FIG. 3A, the first inorganic encapsulation layer 142,the organic encapsulation layer 144, the pad electrodes 172 and 182, thefirst and second routing pads 176 and 186, the first conductive layer156 a of the first routing lines 156 and the first conductive layer ofthe second routing lines 166 are formed on the substrate 111 providedwith the switching transistors, the driving transistors, the anodes 122,the organic light emitting layer 124 and the cathodes 126 formedthereon.

In more detail, an inorganic insulating material and an organicinsulating material are sequentially stacked on the substrate 111,provided with the switching transistors, the driving transistors, theanodes 122, the organic light emitting layer 124 and the cathodes 126formed thereon, through a deposition process using a metal mask, therebyforming the first inorganic encapsulation layer 142 and the organicencapsulation layer 144. The first inorganic encapsulation layer 142 andthe organic encapsulation layer 144 are formed in other regions exceptfor a region in which touch driving pads and touch signal pads will beformed. Thereafter, a first conductive layer is deposited on the entiresurface of the organic encapsulation layer 144, and the first conductivelayer is then patterned through a photolithography process and anetching process, thereby forming the first and second routing pads 176and 186, the first conductive layer 156 a of the first routing lines156, the first conductive layer of the second routing lines 166 and thepad electrodes 172 and 182. Here, the first conductive layer 156 a andthe pad electrodes 172 and 182 are formed to have a monolayer ormultilayer structure using metals having high corrosion resistance andacid resistance, such as Al, Ti, Cu and Mo. For example, the firstconductive layer 156 a has a tri-layer structure, such as Ti/Al/Ti orMo/Al/Mo.

Thereafter, with reference to FIG. 3B, the first and second routing pads176 and 186, the second conductive layer 156 b of the first routinglines 156, the second conductive layer of the second routing lines 166and the first bridges 152 b are formed on the substrate 111 providedwith the first conductive layer 156 a and the pad electrodes 172 and182.

In more detail, a second conductive layer is deposited on the entiresurface of the substrate 111 provided with the first conductive layer156 a and the pad electrodes 172 and 182, and the second conductivelayer is then patterned through a photolithography process and anetching process, thereby forming the first and second routing pads 176and 186, the second conductive layer 156 b of the first routing lines156, the second conductive layer of the second routing lines 166 and thefirst bridges 152 b. Here, the second conductive layer 156 b and thefirst bridge 152 b are formed of a transparent conductive layer, such asan ITO, IZO, IGZO or ZnO-based transparent conductive oxide.

Thereafter, with reference to FIG. 3C, the second inorganicencapsulation layer 146 having the touch contact holes 150, the firstand second routing contact holes 158 and 168 and the pad contact holes160 is formed on the substrate 111 provided with the second conductivelayer 156 b and the first bridges 152 b.

In more detail, an inorganic insulating material is deposited on thesubstrate 111 provided with the second conductive layer 156 b and thefirst bridges 152 b through a deposition process using a metal mask soas to expose pad electrodes, thereby forming the second inorganicencapsulation layer 146. Thereafter, the second inorganic encapsulationlayer 146 is patterned through a photolithography process and an etchingprocess, thereby forming the touch contact holes 150, the routingcontact holes 158 and 168 and the pad contact holes 160. The touchcontact holes 150 are formed through the second inorganic encapsulationlayer 146 and thus expose the first bridges 152 b, the first and secondrouting contact holes 158 and 168 are formed through the secondinorganic encapsulation layer 146 and thus expose the first and secondrouting lines 156 and 166, and the pad contact holes 160 are formedthrough the second inorganic encapsulation layer 146 and thus expose thefirst and second routing pads 176 and 186.

Thereafter, with reference to FIG. 3D, the first and second touchelectrodes 152 e and 154 e, the second bridges 154 b and the padconnection electrodes 174 and 184 are formed on the substrate 111provided with the second inorganic encapsulation layer 146.

In more detail, third and fourth conductive layers are deposited on theentire surface of the substrate 111 provided with the second inorganicencapsulation layer 146 and, then, a photoresist pattern having amulti-stepped structure is formed on the fourth conductive layer througha photolithography process using a slit mask or a diffraction mask. Thethird and fourth conductive layers are primarily etched through anetching process using such a photoresist pattern as a mask. Thereafter,after ashing of the photoresist pattern, the fourth conductive layer issecondarily etched through an etching process using the ashedphotoresist pattern as a mask. Thereby, the first and second touchelectrodes 152 e and 154 e and the second bridges 154 b formed of thethird conductive layer 174 a are formed and, simultaneously, the padconnection electrodes 174 and 184, in which the third and fourthconductive layers 174 a and 174 b are stacked, are formed. Here, thefirst touch electrodes 152 e are conductively connected to the firstbridges 152 b exposed through the touch contact holes 150, and the padconnection electrodes 174 and 184 are conductively connected to thefirst and second routing pads 176 and 186 exposed through the padcontact holes 160 and are directly connected to the pad electrodes 172and 182 without contact holes.

FIG. 4 is a plan view of an organic light emitting display having touchsensors in accordance with a further embodiment of the presentinvention, and FIG. 5 is a cross-sectional view of the organic lightemitting display, taken along line II-IF of FIG. 4.

The organic light emitting display shown in FIGS. 4 and 5 is the same asthe organic light emitting display shown in FIGS. 1 and 2, except thattouch sensing lines 154 and touch driving lines 152 are disposed so asto intersect each other with an organic encapsulation layer 144interposed therebetween. Therefore, a detailed description of elementsof the organic light emitting display shown in FIGS. 4 and 5, which aresubstantially the same as those of the organic light emitting displayshown in FIGS. 1 and 2, will be omitted because it is considered to beunnecessary.

The touch driving line 152 includes a plurality of first touchelectrodes 152 e disposed on the organic encapsulation layer 144, andfirst bridges 152 b to conductively connect the first touch electrodes152 e. The first bridges 152 b are formed on a first inorganicencapsulation layer 142 and exposed through touch contact holes 150formed through the organic encapsulation layer 144, and are conductivelyconnected to the first touch electrodes 152 e.

The touch sensing line 154 includes a plurality of second touchelectrodes 154 e, and second bridges 154 b to conductively connect thesecond touch electrodes 154 e. The second touch electrodes 154 e and thesecond bridges 154 b are disposed on the organic encapsulation layer 144and conductively connected to each other without contact holes.

Since the touch sensing lines 154 and the touch driving lines 152intersect each other with the organic encapsulation layer 144 interposedtherebetween, mutual capacitances Cm are formed at the intersectionsbetween the touch sensing lines 154 and the touch driving lines 152.Therefore, the mutual capacitance Cm is charged with charges by a touchdriving pulse supplied to the touch driving line 152 and discharges thecharges to the touch sensing line 154, thus serving as a touch sensor.

Each of touch driving pads 170 and touch sensing pads 180 includes a padelectrode 172 or 182 and a pad connection electrode 174 or 184 disposedon the pad electrode 172 or 182 so as to cover the pad electrode 172 or182. The pad connection electrodes 174 and 184 of the touch driving pads170 and the touch sensing pads 180 are conductively connected to firstand second routing pads 176 and 186 exposed through first pad contactholes 160 formed through the organic encapsulation layer 144 and secondpad contact holes 162 formed through a second inorganic encapsulationlayer 146. The pad electrodes 172 and 182 of the touch driving pads 170and the touch sensing pads 180 are formed of a first conductive layer,and the pad connection electrodes 174 and 184 are formed of a fourthconductive layer having a monolayer or multilayer structure using metalshaving high corrosion resistance and acid resistance, such as Al, Ti, Cuand Mo. For example, the fourth conductive layer has a tri-layerstructure, such as Ti/Al/Ti or Mo/Al/Mo.

As such, in the organic light emitting display in accordance with thisembodiment of the present invention, the touch driving lines 152 and thetouch sensing lines 154 are disposed so as to intersect each other withthe organic encapsulation layer 144 of the encapsulation unit 140interposed therebetween, thereby achieving structure simplification,weight reduction and slimming. In this instance, the organic lightemitting display in accordance with the present invention does notrequire a touch insulating layer having a multilayer structure in atouchscreen, as compared to a related art organic light emittingdisplay, and can thus achieve structure simplification, weight reductionand slimming, assure flexibility and improve transmittance. Further,while, in the related art organic light emitting display, a touchscreenis attached to a display panel through an adhesive, in the organic lightemitting display in accordance with the present invention, the touchelectrodes 152 e and 154 e are disposed in the encapsulation unit 140, aseparate attachment process is omitted and, thus, process simplificationand cost reduction can be achieved.

FIGS. 6A to 6F are plan and cross-sectional views illustrating a methodof fabricating the organic light emitting display shown in FIGS. 4 and5.

With reference to FIG. 6A, the first inorganic encapsulation layer 142,the pad electrodes 172 and 182, the first and second routing pads 176and 186, the first conductive layer 156 a of the first routing lines 156and the first conductive layer of the second routing lines 166 areformed on the substrate 111 provided with switching transistors, drivingtransistors, anodes 122, the organic light emitting layer 124 andcathodes 126 formed thereon.

In more detail, an inorganic insulating material is stacked on thesubstrate 111, provided with the switching transistors, the drivingtransistors, the anodes 122, the organic light emitting layer 124 andthe cathodes 126 formed thereon, through a deposition process using ametal mask, thereby forming the first inorganic encapsulation layer 142.The first inorganic encapsulation layer 142 is formed in other regionsexcept for a region in which touch driving pads and touch signal padswill be formed. Thereafter, a first conductive layer is deposited on theentire surface of the first inorganic encapsulation layer 142, and thefirst conductive layer is then patterned through a photolithographyprocess and an etching process, thereby forming the first and secondrouting pads 176 and 186, the first conductive layer 156 a of the firstrouting lines 156, the first conductive layer of the second routinglines 166 and the pad electrodes 172 and 182. Here, the first conductivelayer 156 a and the pad electrodes 172 and 182 are formed to have amonolayer or multilayer structure using metals having high corrosionresistance and acid resistance, such as Al, Ti, Cu and Mo. For example,the first conductive layer 156 a has a tri-layer structure, such asTi/Al/Ti or Mo/Al/Mo.

Thereafter, with reference to FIG. 6B, the first and second routing pads176 and 186, the second conductive layer 156 b of the first routinglines 156, the second conductive layer of the second routing lines 166and the first bridges 152 b are formed on the substrate 111 providedwith the first conductive layer 156 a and the pad electrodes 172 and182.

In more detail, a second conductive layer is deposited on the entiresurface of the substrate 111 provided with the first conductive layer156 a and the pad electrodes 172 and 182, and the second conductivelayer is then patterned through a photolithography process and anetching process, thereby forming the first and second routing pads 176and 186, the second conductive layer 156 b of the first routing lines156, the second conductive layer of the second routing lines 166 and thefirst bridges 152 b. Here, the second conductive layer 156 b and thefirst bridge 152 b are formed of an ITO, IZO, IGZO or ZnO-basedtransparent conductive oxide.

Thereafter, with reference to FIG. 6C, the organic encapsulation layer144 having touch contact holes 150, first and second routing contactholes 158 and 168 and first pad contact holes 160 is formed on thesubstrate 111 provided with the second conductive layer 156 b and thefirst bridges 152 b.

In more detail, an organic insulating material is deposited on thesubstrate 111 provided with the second conductive layer 156 b and thefirst bridges 152 b through a deposition process using a metal mask soas to expose pad electrodes 172 and 182, thereby forming the organicencapsulation layer 144. Thereafter, the organic encapsulation layer 144is patterned through a photolithography process and an etching process,thereby forming the touch contact holes 150, the routing contact holes158 and 168 and the first pad contact holes 160. The touch contact holes150 are formed through the organic encapsulation layer 144 and thusexpose the first bridges 152 b, the first and second routing contactholes 158 and 168 are formed through the organic encapsulation layer 144and thus expose the first and second routing lines 156 and 166, and thefirst pad contact holes 160 are formed through the organic encapsulationlayer 144 and thus expose the first and second routing pads 176 and 186.

Thereafter, with reference to FIG. 6D, the first and second touchelectrodes 152 e and 154 e and the second bridges 154 b are formed onthe substrate 111 provided with the organic encapsulation layer 144.

In more detail, a third conductive layer is deposited on the entiresurface of the substrate 111 provided with the organic encapsulationlayer 144, and the third conductive layer is then patterned through aphotolithography process and an etching process, thereby forming thefirst and second touch electrodes 152 e and 154 e and the second bridges154 b. Here, the first touch electrodes 152 e are conductively connectedto the first bridges 152 b exposed through the touch contact holes 150.Here, the third conductive layer is formed of an ITO, IZO, IGZO orZnO-based transparent conductive oxide.

Thereafter, with reference to FIG. 6E, the second inorganicencapsulation layer 146 having second pad contact holes 162 is formed onthe substrate 111 provided with the first and second touch electrodes152 e and 154 e and the second bridges 154 b.

In more detail, an inorganic insulating material is deposited on thesubstrate 111 provided with the first and second touch electrodes 152 eand 154 e and the second bridges 154 b through a deposition processusing a metal mask so as to expose the pad electrodes 172 and 182,thereby forming the second inorganic encapsulation layer 146.Thereafter, the second inorganic encapsulation layer 146 is patternedthrough a photolithography process and an etching process, therebyforming the second pad contact holes 162. The second pad contact holes162 are formed through the second inorganic encapsulation layer 146,thus being connected to the first pad contact holes 160 vertically.

Thereafter, with reference to FIG. 6F, pad connection electrodes 174 and184 are formed on the substrate 111 provided with the second inorganicencapsulation layer 146 having the second pad contact holes 162.

In more detail, a fourth conductive layer is deposited on the entiresurface of the substrate 111 provided with the second inorganicencapsulation layer 146 having the second pad contact holes 162, and thefourth conductive layer is then patterned through a photolithographyprocess and an etching process, thereby forming the pad connectionelectrodes 174 and 184 of the touch sensing pads 170 and the touchdriving pads 180. The pad connection electrodes 174 and 184 are directlyconnected to the pad electrodes 172 and 182, and are connected to therouting pads 176 and 186 through the first and second pad contact holes160 and 162.

FIG. 7 is a cross-sectional view of an organic light emitting displayhaving touch sensors in accordance with another embodiment of thepresent invention.

The organic light emitting display shown in FIG. 7 is the same as theorganic light emitting display shown in FIGS. 1 and 2, except that touchsensing lines 154 and touch driving lines 152 are disposed so as tointersect each other with a first inorganic encapsulation layer 142interposed therebetween. Therefore, a detailed description of elementsof the organic light emitting display shown in FIG. 7, which aresubstantially the same as those of the organic light emitting displayshown in FIGS. 1 and 2, will be omitted because it is considered to beunnecessary.

The touch driving line 152 includes a plurality of first touchelectrodes 152 e disposed on the first inorganic encapsulation layer142, and first bridges 152 b to conductively connect the first touchelectrodes 152 e. The first bridges 152 b are formed on an interlayerinorganic layer 148, are exposed through touch contact holes 150 formedthrough the first inorganic encapsulation layer 142, and areconductively connected to the first touch electrodes 152 e. Here, theinterlayer inorganic layer 148 is formed of an inorganic insulatingmaterial which can be deposited at a low temperature, such as siliconnitride (SiN_(x)), silicon oxide (SiO_(x)), silicon oxynitride (SiON) oraluminum oxide (Al₂O₃), in the same manner as the first inorganicencapsulation layer 142.

The touch sensing line 154 includes a plurality of second touchelectrodes 154 e, and second bridges 154 b to conductively connect thesecond touch electrodes 154 e. The second touch electrodes 154 e and thesecond bridges 154 b are disposed on the first inorganic encapsulationlayer 142 and are conductively connected to each other without contactholes.

Since the touch sensing lines 154 and the touch driving lines 152intersect each other with the first inorganic encapsulation layer 142interposed therebetween, mutual capacitances Cm are formed at theintersections between the touch sensing lines 154 and the touch drivinglines 152. Therefore, the mutual capacitance Cm is charged with chargesby a touch driving pulse supplied to the touch driving line 152 anddischarges the charges to the touch sensing line 154, thus serving as atouch sensor.

Each of touch driving pads 170 and touch sensing pads 180 includes a padelectrode 172 or 182 and a pad connection electrode 174 or 184 disposedon the pad electrode 172 or 182 so as to cover the pad electrode 172 or182. The pad connection electrodes 174 and 184 of the touch driving pads170 and the touch sensing pads 180 are conductively connected to firstand second routing pads 176 and 186 exposed through first pad contactholes 160 formed through the first inorganic encapsulation layer 142 andsecond pad contact holes 162 formed through the organic encapsulationlayer 144 and the second inorganic encapsulation layer 146. The padelectrodes 172 and 182 of the touch driving pads 170 and the touchsensing pads 180 are formed of a first conductive layer, and the padconnection electrodes 174 and 184 are formed of a fourth conductivelayer having a monolayer or multilayer structure using metals havinghigh corrosion resistance and acid resistance, such as Al, Ti, Cu andMo. For example, the fourth conductive layer has a tri-layer structure,such as Ti/Al/Ti or Mo/Al/Mo.

As such, in the organic light emitting display in accordance with thisembodiment of the present invention, the touch driving lines 152 and thetouch sensing lines 154 are disposed so as to intersect each other withthe first inorganic encapsulation layer 142 of the encapsulation unit140 interposed therebetween, thereby achieving structure simplification,weight reduction and slimming. In this instance, the organic lightemitting display in accordance with the present invention does notrequire a touch insulating layer having a multilayer structure in atouchscreen, as compared to a related art organic light emittingdisplay, and can thus achieve structure simplification, weight reductionand slimming, assure flexibility and improve transmittance. Further,while, in the related art organic light emitting display, a touchscreenis attached to a display panel through an adhesive, in the organic lightemitting display in accordance with the present invention, touchelectrodes 152 e and 154 e are disposed in the encapsulation unit 140, aseparate attachment process is omitted and, thus, process simplificationand cost reduction can be achieved.

FIGS. 8A to 8F are cross-sectional views illustrating a method offabricating the organic light emitting display shown in FIG. 7.

With reference to FIG. 8A, the interlayer inorganic layer 148, the padelectrodes 172 and 182, the first and second routing pads 176 and 186,the first conductive layer 156 a of the first routing lines 156 and thefirst conductive layer of the second routing lines 166 are formed on thesubstrate 111 provided with switching transistors, driving transistors,anodes 122, the organic light emitting layer 124 and cathodes 126 formedthereon.

In more detail, an inorganic insulating material is stacked on thesubstrate 111, provided with the switching transistors, the drivingtransistors, the anodes 122, the organic light emitting layer 124 andthe cathodes 126 formed thereon, through a deposition process using ametal mask, thereby forming the interlayer inorganic layer 148. Theinterlayer inorganic layer 148 is formed in other regions except for aregion in which touch driving pads and touch signal pads will be formed.Thereafter, a first conductive layer is deposited on the entire surfaceof the interlayer inorganic layer 148, and the first conductive layer isthen patterned through a photolithography process and an etchingprocess, thereby forming the first and second routing pads 176 and 186,the first conductive layer 156 a of the first routing lines 156, thefirst conductive layer of the second routing lines 166 and the padelectrodes 172 and 182. Here, the first conductive layer 156 a and thepad electrodes 172 and 182 are formed to have a monolayer or multilayerstructure using metals having high corrosion resistance and acidresistance, such as Al, Ti, Cu and Mo. For example, the first conductivelayer 156 a has a tri-layer structure, such as Ti/Al/Ti or Mo/Al/Mo.

Thereafter, with reference to FIG. 8B, the first and second routing pads176 and 186, the second conductive layer 156 b of the first routinglines 156, the second conductive layer of the second routing lines 166and the first bridges 152 b are formed on the substrate 111 providedwith the first conductive layer 156 a and the pad electrodes 172 and182.

In more detail, a second conductive layer is deposited on the entiresurface of the substrate 111 provided with the first conductive layer156 a and the pad electrodes 172 and 182, and the second conductivelayer is then patterned through a photolithography process and anetching process, thereby forming the first and second routing pads 176and 186, the second conductive layer 156 b of the first routing lines156, the second conductive layer of the second routing lines 166 and thefirst bridges 152 b. Here, the second conductive layer 156 b and thefirst bridge 152 b are formed of an ITO, IZO, IGZO or ZnO-basedtransparent conductive oxide.

Thereafter, with reference to FIG. 8C, the first inorganic encapsulationlayer 142 having touch contact holes 150, first and second routingcontact holes 158 and 168 and first pad contact holes 160 is formed onthe substrate 111 provided with the second conductive layer 156 b andthe first bridges 152 b.

In more detail, an inorganic insulating material is deposited on thesubstrate 111 provided with the second conductive layer 156 b and thefirst bridges 152 b through a deposition process using a metal mask soas to expose pad electrodes 172 and 182, thereby forming the firstinorganic encapsulation layer 142. Thereafter, the first inorganicencapsulation layer 142 is patterned through a photolithography processand an etching process, thereby forming the touch contact holes 150, therouting contact holes 158 and 168 and the first pad contact holes 160.The touch contact holes 150 are formed through the first inorganicencapsulation layer 142 and thus expose the first bridges 152 b, thefirst and second routing contact holes 158 and 168 are formed throughthe first inorganic encapsulation layer 142 and thus expose the firstand second routing lines 156 and 166, and the first pad contact holes160 are formed through the first inorganic encapsulation layer 142 andthus expose the first and second routing pads 176 and 186.

Thereafter, with reference to FIG. 8D, the first and second touchelectrodes 152 e and 154 e and the second bridges 154 b are formed onthe substrate 111 provided with the first inorganic encapsulation layer142.

In more detail, a third conductive layer is deposited on the entiresurface of the substrate 111 provided with the first inorganicencapsulation layer 142, and the third conductive layer is thenpatterned through a photolithography process and an etching process,thereby forming the first and second touch electrodes 152 e and 154 eand the second bridges 154 b. Here, the first touch electrodes 152 e areconductively connected to the first bridges 152 b exposed through thetouch contact holes 150.

Thereafter, with reference to FIG. 8E, the organic encapsulation layer144 and the second inorganic encapsulation layer 146 having second padcontact holes 162 is formed on the substrate 111 provided with the firstand second touch electrodes 152 e and 154 e and the second bridges 154b.

In more detail, an organic insulating material and an inorganicinsulating material are sequentially deposited on the substrate 111provided with the first and second touch electrodes 152 e and 154 e andthe second bridges 154 b through a deposition process using a metalmask, thereby forming the organic encapsulation layer 144 and the secondinorganic encapsulation layer 146. Thereafter, the organic encapsulationlayer 144 and the second inorganic encapsulation layer 146 are patternedthrough a photolithography process and an etching process, therebyforming the second pad contact holes 162. The second pad contact holes162 are formed through the organic encapsulation layer 144 and thesecond inorganic encapsulation layer 146, thus being connected to thefirst pad contact holes 160 vertically.

Thereafter, with reference to FIG. 8F, pad connection electrodes 174 and184 are formed on the substrate 111 provided with the second inorganicencapsulation layer 146 having the second pad contact holes 162.

In more detail, a fourth conductive layer is deposited on the entiresurface of the substrate 111 provided with the second inorganicencapsulation layer 146 having the second pad contact holes 162, and thefourth conductive layer is then patterned through a photolithographyprocess and an etching process, thereby forming the pad connectionelectrodes 174 and 184 of the touch sensing pads 170 and the touchdriving pads 180. The pad connection electrodes 174 and 184 are directlyconnected to the pad electrodes 172 and 182, and are connected to therouting pads 176 and 186 through the first and second pad contact holes160 and 162.

Although the above-described embodiments of the present inventionexemplarily describe that the routing lines 156 and 166 and the padelectrodes 172 and 182 are conductively connected through the routingpads 176 and 186 and the pad connection electrodes 174 and 184, padelectrodes 172 can extend from the routing lines 156, as exemplarilyshown in FIG. 9, and thus the routing lines 156 and the pad electrodes172 can be conductively connected directly to each other without routingpads 176 and 186 and pad connection electrodes 174 and 184. In thisinstance, the routing lines 156 are disposed on the side and uppersurfaces of any one of remaining encapsulation layers except for anencapsulation layer located at the uppermost position of anencapsulation unit 140. For example, as exemplarily shown in FIG. 9, therouting lines 156 are disposed on the side and upper surfaces of theorganic encapsulation layer 144 located under the second inorganicencapsulation layer 146 located at the uppermost position of theencapsulation unit 140. Thereby, if moisture penetrates through therouting lines 156 and the pad electrodes 172, the first inorganicencapsulation layer 142 and the organic encapsulation layer 144 canblock moisture.

Further, the touch sensing lines 154 and the touch driving lines 152 inaccordance with the above-described embodiments of the present inventionare protected by a protective film 190, as exemplarily shown in FIG. 10.As the protective film 190, a circularly polarizing plate can be used ora separate film formed of epoxy or acryl can be used.

Moreover, although the present invention exemplarily illustrates thatthe bridges 152 b and the first touch electrodes 152 e of the touchdriving lines 152 are disposed on different planes and are thenconnected through the touch contact holes 150, the bridges 154 b and thesecond touch electrodes 154 e of the touch sensing lines 154 can bedisposed on different planes and be then connected through touch contactholes.

As apparent from the above description, in an organic light emittingdisplay having touch sensors in accordance with the present invention,touch driving lines and touch sensing lines are disposed so as tointersect each other with at least one of a first inorganicencapsulation layer, a second inorganic encapsulation layer and anorganic encapsulation layer of an encapsulation unit, interposedtherebetween. Therefore, the organic light emitting display inaccordance with the present invention does not require a touchinsulating layer, which is disposed between touch driving lines andtouch sensing lines of a related art organic light emitting display, andmay thus achieve structure simplification, weight reduction andslimming. Further, the organic light emitting display in accordance withthe present invention can assure flexibility and enhance transmittance.Moreover, the organic light emitting display in accordance with thepresent invention disposes touch electrodes in the encapsulation unitand does not require a separate attachment process, thereby simplifyingthe overall process and reducing manufacturing costs.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. An organic light emitting display comprising:light emitting elements disposed on a substrate; an encapsulation unitdisposed on the light emitting elements; touch sensors disposed on theencapsulation unit; first conductive lines connected to the touchsensors; second conductive lines connected to the first conductivelines; and at least one insulating film formed of at least one of aninorganic film or an organic film and disposed between the first andsecond conductive lines.
 2. The organic light emitting display accordingto claim 1, wherein at least parts of the first and second conductivelines overlap each other in an edge area of the substrate.
 3. Theorganic light emitting display according to claim 1, wherein the firstand second conductive lines overlap each other on the encapsulationunit.
 4. The organic light emitting display according to claim 1,wherein the first and second conductive lines are connected throughcontact holes formed through the at least one insulating film.
 5. Theorganic light emitting display according to claim 1, further comprisingtouch pads connected to the second conductive lines and disposed on thesubstrate having the light emitting elements disposed thereon.
 6. Theorganic light emitting display according to claim 1, wherein the touchsensors comprise: a plurality of first touch electrodes and a pluralityof second touch electrodes; first bridges configured to connect thefirst touch electrodes; and second bridges configured to connect thesecond touch electrodes.
 7. The organic light emitting display accordingto claim 6, wherein one of the first and the second bridges is disposedon a same plane as one of the first and second conductive lines.
 8. Theorganic light emitting display according to claim 6, wherein at leastone of the first bridges, the second bridges, the first touchelectrodes, the second touch electrodes, the first conductive lines orthe second conductive lines is formed in a multilayer structurecomprising Al, Ti, Cu, Mo, ITO or IZO.
 9. The organic light emittingdisplay according to claim 6, wherein at least one of the first bridges,the second bridges, the first touch electrodes, the second touchelectrodes, the first conductive lines or the second conductive lines isformed of Ti/Al/Ti or Mo/Al/Mo.
 10. The organic light emitting displayaccording to claim 6, further comprising a bank configured to exposeanodes of the light emitting elements, wherein at least one of the firstbridges or the second bridges overlaps the bank.
 11. The organic lightemitting display according to claim 6, wherein: the encapsulation unitcomprises at least one inorganic encapsulation layer and at least oneorganic encapsulation layer; and the at least one insulating film is oneof the at least one inorganic encapsulation layer and the at least oneorganic encapsulation layer.
 12. The organic light emitting displayaccording to claim 11, wherein the second conductive lines are disposedon an uppermost one of the at least one inorganic encapsulation layer.13. The organic light emitting display according to claim 12, whereinthe first conductive lines are disposed on the at least one organicencapsulation layer.
 14. The organic light emitting display according toclaim 13, wherein the first conductive lines are connected to the secondconductive lines through contact holes formed through the uppermost oneof the at least one inorganic encapsulation layer.
 15. The organic lightemitting display according to claim 12, wherein the first conductivelines are disposed on one of the at least one inorganic encapsulationlayer, disposed under the at least one organic encapsulation layer. 16.The organic light emitting display according to claim 15, wherein thefirst conductive lines are connected to the second conductive linesthrough contact holes formed through the uppermost one of the at leastone inorganic encapsulation layer and through the at least one organicencapsulation layer.
 17. The organic light emitting display according toclaim 12, further comprising an interlayer inorganic layer disposed oncathodes of the light emitting elements, wherein the first conductivelines are disposed on the interlayer inorganic layer.
 18. The organiclight emitting display according to claim 17, wherein the firstconductive lines are connected to the second conductive lines throughcontact holes formed through the at least one inorganic encapsulationlayer and the at least one organic encapsulation layer.
 19. The organiclight emitting display according to claim 1, wherein the secondconductive lines are disposed along a side surface of the encapsulationunit.
 20. The organic light emitting display according to claim 11,wherein the second conductive lines contact an uppermost one of the atleast one inorganic encapsulation layer.